Oleandomycin, its production in fermentation broths and its use as an antibacterial agent were first described in U.S. Pat. No. 2,757,123, the disclosure of which is incorporated herein by reference. The naturally occurring compound is known to have the structure: ##STR1## The conventionally accepted number scheme is shown at a variety of positions. Several synthetic modifications of this compound are known, particularly those in which from one to three of the free hydroxyl groups found at the 2', 4" and 11-positions are esterified as acetyl esters. There are described in U.S. Pat. No. 3,022,219 other modifications in which the acetyl in the above-mentioned esters is replaced with another, preferably unbranched alkanoyl having from two to six carbon atoms or trifluoroacetyl moiety.
Also known are semi-synthetic oleandomycins in which one or several of the hydrogens of the hydroxyl groups mentioned above are replaced with a tri(lower alkyl)silyl and preferably a trimethyl silyl group.